Need Help With Some Reverse Engineering

Hi there!

I’m trying to follow a tutorial to create this slide (as an open surface) but I’m losing my mind on how to do so…
I’ve tried sweep 1,2 but to no avail
I tried to dup the edges (rail + 2 sections) but Im not sure how to get around this…

Any help would be appreciated!
Thanks

Slide-Open Surface.3dm (449.8 KB)

the surface can be build by:
_sweep1 (red: rail, green 2xcross)
_trim (cyan as cutter)

to understand how the surface was build - the surface is trimmed - a nurbs-surfaces with areas that are cut away by a trim-curve:
_untrimall
to “extract” the initial data:
_extractIsocurve
_dupEdge

hope that helps, kind regards - tom

Slide-Open Surface_tomhelps.3dm (341.3 KB)

to learn Rhino you can also have a look at:
https://wiki.mcneel.com/rhino/6/trainingguides/en

Ahh thanks so much Tom!! Seriously saved me from crashing my head into the screen!
Thanks!!